Objective To examine the epigenetic expression of androgen induced suppression of follicular epithelial cell proliferation by dermal papilla cells derived from nonbald frontal scalps of prepubertal stumptailed macaques. ABSTRACT:Our previous study revealed that dermal papilla cells from the bald frontal scalp (bFDP) of the stumptailed macaque play a role in testosterone (T)-dependent inhibition of follicular cell proliferation. Most macaques begin to develop early signs of baldness after the age of puberty (4 years) with the elevation of serum T/DHT in both sexes. This study was aimed to examine whether the dermal papilla cells obtained from the nonbald frontal scalp (nFDP) of prepubertal macaques express T-dependent inhibition of follicular cell growth. The dermal papilla cells obtained from both nonbald prepubertal (2yr) and bald adult (7-12 yr) frontal scalps were cultured with DMEM supplemented with T-free FBS medium. Simultaneously, the outer root sheath cells obtained from the occipital scalp were cultured with KGM. The size (mean longitudinal length) of the isolated nFDP (81.2q3.7 m) was comparable to the size of DP from the occipital scalp (ODP) in prepubertal macaques (84.0q4.4 m), whereas the size of bFDP (75.0q5.2 m) was smaller than that of ODP of postpubertal macaques (153.1q4.8 m). The mean doubling time of nFDP cells (37.0q1.6) was significantly (p<0.01) shorter than that of bFDP cells (69.0q5.9 h). T (10-10~10-7M) showed no effects on proliferation of either type of cultured FDP cells and T (10-10M) had no effect on proliferation of cultured ORS cells. When FDP (n and b) and ORS (n and b) cells were cocultured in the same well, their total cell number significantly increased compared to the sum of the number of FDP and ORS cells cultured alone. T (10-10M) completely inhibited the cell proliferation enhanced by coculture of bFDP and ORS cells. RU58841, a potent non-steroidal androgen receptor blocker, antagonized this T-elicited inhibition. However, the total number of cocultured nFDP and ORS cells was not affected by T. We suggest that the role of DP cells in T-dependent inhibitory action to ORS cells is linked to hereditary factors and an elevation of postpubertal testosterone can initiate and promote this epigenetic expression of the frontal dermal papilla cells. Keywords cell culture hair follicle androgenetic alopecia testosterone